Pie dough: Add wheat flour, sugar and butter in pieces in the bowl to the food processor with the knife mounted. Drive to a crumbly mass.
Add the egg yolk and run until it becomes a dough.
Press out the dough into a pie mold, about 24 inches in diameter. Place and place in the fridge for at least 30 minutes.
Filling: Set oven to 200 degrees. Cut the pumpkin into cubes and mill in a saucepan with butter for about 10 minutes. Add to the food processor and mix to a puree. Let cool.
Add eggs, mustard and muscovado sugar, cornstarch, cream, cinnamon, ginger, nutmeg and salt. Drive to a smooth batter. Pour the filling into the pie mold. Bake in the bottom of the oven for about 45 minutes. Let cool.
Whip the cream and season with muscovado syrup. Aim over icing sugar. Sprinkle cream on the pie and garnish with mint.